A pulse oximeter that is capable of measuring oxygen saturation of blood (SpO2) is known. In this pulse oximeter, a measurement part that is worn on a part of a body of a subject shines light onto the part of the body, and SpO2 is derived based on the amount of light that passes through or is reflected off the part of the body.
As for this pulse oximeter, a device in which a light source, a sensor, a processor, an amplifier, and the like are arranged in an integrated housing has been proposed (e.g., European Patent No. 1830695). This configuration reduces the manufacturing cost for the device, and makes the device less prone to breakage. Another device that includes a body part to be worn on a wrist and a probe to be fixed on a finger with a strip-shaped tape has been proposed (e.g., Japanese Patent Application Laid-Open No. 2005-110816).